This paper shows the importance of the incompressibility of nuclear matter on analyzing the fusion excitation functions, average angular momenta, and astrophysical S factor at energies far below the Coulomb barrier for the asymmetric systems 28Si + 94Mo and 28Si + 100Mo. Moreover, our predictions for threshold energy of fall-off phenomena, ES , are in good agreement with semi-empirical formulas of ES for 28Si + 94,100Mo systems.